import java.util.ArrayList;
import java.util.List;

public class seeOk {
    public static void main(String[] args) {
        A a = new B();
        System.out.println(a.a);
        a.test();
    }
}

class A{
    public int a = 10;
    public void test(){
        System.out.println("a");
    }
}
class B extends A{
    public int a = 15;
    public void test(){
        System.out.println("b");
    }
}
